Non-equilibrium Casimir forces: Spheres and sphere-plate

We discuss non-equilibrium extensions of the Casimir force (due to electromagnetic fluctuations), where the objects as well as the environment are held at different temperatures. While the formalism we develop is quite general, we focus on a sphere in front of a plate, as well as two spheres, when the radius is small compared to separation and thermal wavelengths. In this limit the forces can be expressed analytically in terms of the lowest order multipoles, and corroborated with results obtained by diluting parallel plates of vanishing thickness. Non-equilibrium forces are generally stronger than their equilibrium counterpart, and may oscillate with separation (at a scale set by material resonances). For both geometries we obtain stable points of zero net force, while two spheres may have equal forces in magnitude and direction resulting in a self-propelling state.Comment: 6 pages, 6 figure

Perspectives on weak interactions in complex materials at different length scales

Nanocomposite materials consist of nanometer-sized quantum objects such as atoms, molecules, voids or nanoparticles embedded in a host material. These quantum objects can be exploited as a super-structure, which can be designed to create material properties targeted for specific applications. For electromagnetism, such targeted properties include field enhancements around the bandgap of a semiconductor used for solar cells, directional decay in topological insulators, high kinetic inductance in superconducting circuits, and many more. Despite very different application areas, all of these properties are united by the common aim of exploiting collective interaction effects between quantum objects. The literature on the topic spreads over very many different disciplines and scientific communities. In this review, we present a cross-disciplinary overview of different approaches for the creation, analysis and theoretical description of nanocomposites with applications related to electromagnetic properties

Perspectives on weak interactions in complex materials at different length scales

Nanocomposite materials consist of nanometer-sized quantum objects such as atoms, molecules, voids or nanoparticles embedded in a host material. These quantum objects can be exploited as a super-structure, which can be designed to create material properties targeted for specific applications. For electromagnetism, such targeted properties include field enhancements around the bandgap of a semiconductor used for solar cells, directional decay in topological insulators, high kinetic inductance in superconducting circuits, and many more. Despite very different application areas, all of these properties are united by the common aim of exploiting collective interaction effects between quantum objects. The literature on the topic spreads over very many different disciplines and scientific communities. In this review, we present a cross-disciplinary overview of different approaches for the creation, analysis and theoretical description of nanocomposites with applications related to electromagnetic properties

A systematic review of impulse control disorders in Parkinson's disease.

Throughout the past decade it has been recognized that dopaminergic medication administered to remedy motor symptoms in Parkinson's disease is associated with an enhanced risk for impulse control disorders and related compulsive behaviors such as hobbyism, punding, and the dopamine dysregulation syndrome. These complications are relatively frequent, affecting 6-15.5% of patients, and they most often appear, or worsen, after initiation of dopaminergic therapy or dosage increase. Recently, impulse control disorders have also been associated with subthalamic nucleus deep brain stimulation. Here we present a systematic overview of literature published between 2000 and January 2013 reporting impulse control disorders in Parkinson's disease. We consider prevalence rates and discuss the functional neuroanatomy, the impact of dopamine-serotonin interactions, and the cognitive symptomatology associated with impulse control disorders in Parkinson's disease. Finally, perspectives for future research and management of impulse control disorders in Parkinson's disease are discussed

Evidence that a nigral gabaergic--cholinergic balance controls posture.

The intranigral injection of kainic acid (k.a.) (3.5 nM/s.n.) produced a lesion which resulted in a decreased muscarinic receptor binding capacity and in a decreased choline acetyl transferase (CAT) activity confined to the pars reticulata. The unilateral, intranigral injection of carbachol in the substantia nigra (s.n.) produced turning, ipsilateral to the injected side, of dose-related intensity, which was antagonized by scopolamine given either i.p. or intranigrally together with carbachol. The bilateral, intranigral injection of carbachol produced rigid catalepsy, highly resistant to apomorphine administration and antagonized by scopolamine. On the other hand, the catalepsy produced by intranigral picrotoxin was much more sensitive to apomorphine and was disrupted by systemic scopolamine administration. Intranigral scopolamine per se produced either contralateral turning or stereotyped movements consistently, when injected unilaterally or bilaterally, respectively. In addition, scopolamine injected bilaterally in the s.n. but not in the caudate nucleus (c.n.), at the concentration of 64 nM side, was able to antagonize the haloperidol-induced catalepsy and to prevent the tremors and the muscular rigidity produced by arecoline. This effect of scopolamine was surmountable with a higher dose of arecoline. Finally, intranigral muscimol (0.44 nM/s.n.) prevented the occurrence of the parkinsonian syndrome produced by systemic arecoline. It is concluded that the muscarinic receptors present in the s.n. pars reticulata play a role in the control of posture opposite to that of the nigral GABA receptors